Why does my NSURL object is equal to nil? My path is correct

问题

NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%lf,%lf&output=csv&sensor=false&key=swizzlec hops", coordinate.latitude,coordinate.longitude];
NSLog(@"urlString: %@", urlString); 
NSURL *urlFromURLString = [NSURL URLWithString:urlString];

My log is : http://maps.google.com/maps/geo?q=53.872874,27.527790&output=csv&sensor=false&key=swizzlec hops

I can copy this url and paste to the browser and its ok, but urlFromURLString = nil. But, why?

回答1:

I believe you need to use

stringByAddingPercentEscapesUsingEncoding:

on urlString before passing it to NSURL.

NSString *urlString = [[NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%lf,%lf&output=csv&sensor=false&key=swizzlec hops", coordinate.latitude,coordinate.longitude] stringByAddingPercentEscapesUsingEncoding::NSUTF8StringEncoding];

回答2:

Try

 NSString *urlString = [[NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%lf,%lf&output=csv&sensor=false&key=swizzlec hops", coordinate.latitude,coordinate.longitude] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];

I don't think you can have spaces in your URL

回答3:

This is a better approach:

NSString* escapedUrl = [originalUrl   stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *urlFromURLString = [NSURL URLWithString:escapedUrl];

来源：https://stackoverflow.com/questions/6505294/why-does-my-nsurl-object-is-equal-to-nil-my-path-is-correct